Specimen Requirements

Preferred Collection Container: green top lithium heparin tube, SST 

Also Acceptable Collection Container: serum red top tube or EDTA purple top tube

Collection Information:

Patient should be on a constant dosage of phenobarbital for at least 18 days before monitoring. Samples should be drawn just before the next dose. If toxicity is suspected, samples can be drawn at any time.

Collect 1.0 mL of Lithium heparinized plasma or serum.

Serum or plasma must be separated from cells within 2 hours of collection.